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UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
448 of 808
NXP Semiconductors
UM10360
Chapter 20: LPC17xx I2S interface
5.
Register description
shows the registers associated with the I
2
S interface and a summary of
their functions. Following the table are details for each register.
I2STX_CLK
Input/Output Transmit Clock. A clock signal used to synchronize the transfer of
data on the transmit channel. It is driven by the master and
received by the slave. Corresponds to the signal SCK in the I
2
S
bus specification.
I2STX_WS
Input/Output Transmit Word Select. Selects the channel to which data is being
sent. It is driven by the master and received by the slave.
Corresponds to the signal WS in the I
2
S bus specification.
WS = 0 indicates that data is being sent to channel 1 (left channel).
WS = 1 indicates that data is being sent to channel 2 (right
channel).
I2STX_SDA
Input/Output Transmit Data. Serial data, sent MSB first. It is driven by the
transmitter and read by the receiver. Corresponds to the signal SD
in the I
2
S bus specification.
TX_MCLK
Output
Optional master clock output for the
I
2
S
transmit function.
Table 384. Pin descriptions
Pin Name
Type
Description
Fig 98. Simple I
2
S configurations and bus timing
TRANSMITTER
(MASTER)
CONTROLLER
(MASTER)
TRANSMITTER
(SLAVE)
RECEIVER
(MASTER)
SCK: serial clock
WS: word select
SD: serial data
TRANSMITTER
(SLAVE)
RECEIVER
(SLAVE)
SCK
WS
SD
SCK
WS
SD
MSB
LSB
MSB
word n
left channel
word n+1
right channel
word n-1
right channel
RECEIVER
(SLAVE)
SCK: serial clock
WS: word select
SD: serial data